This invention relates to mobile communication systems and, more specifically, to keypads for mobile communication devices.
In order for mobile telephones to be conveniently used, they are of a relatively small size. Accordingly, the keypads of such devices are also small. This is particularly the case since, not only are smaller mobile telephones being manufactured, but it is becoming desirable to have larger displays on such devices which means that there is less space available to provide a keypad.
For such small keypads, an important factor is the ease with which they may be used by a user. A keypad should enable a user to select keys rapidly, in a way that is natural, intuitive and without involving unnecessary finger movement.
Keypads for mobile telephones generally have a common, basic, configuration shown in FIG. 1. Keys which are used in dialling numbers, as well as for other purposes, are typically provided in a 4 by 3 matrix having a first row of numerals xe2x80x9c1xe2x80x9d, xe2x80x9c2xe2x80x9d, and xe2x80x9c3xe2x80x9d, a second row of numerals xe2x80x9c4xe2x80x9d, xe2x80x9c5xe2x80x9d, and xe2x80x9c6xe2x80x9d, a third row of numerals xe2x80x9c7xe2x80x9d, xe2x80x9c8xe2x80x9d, and xe2x80x9c9xe2x80x9d and a fourth row having a first character/function key, numeral xe2x80x9c0xe2x80x9d, and a second character/function key. Another arrangement of keys, which is usually located above this arrangement, is used to carry out other functions, such as initiating and terminating telephone calls and navigating around the screen and various menus of a user interface of the mobile telephone.
One disadvantage of this arrangement is that there is little natural spatial correspondence between the locations of the keys and the selectable numerals. For example, although key 6 is adjacent to one key 5 (as a row neighbor), it is also below key 3 and above key 9 (as two column-neighbors). Therefore, use of such a keypad needs to be learned by a user. For example, it is not unusual for a user to remember the input sequence of a telephone number or a code by remembering the pattern of finger movements used in inputting the telephone number or code.
Another disadvantage of such a keypad is that if it is used in an orientation other than the one originally intended, it becomes difficult for a user to select the correct keys. For example, if the keypad of FIG. 1 is rotated clockwise through 90xc2x0, the keys then appear to a user to be in a 3 by 4 matrix and the spatial relationships between keys also appear to have changed. Key 6 now has two row-neighbors, keys 9 and 3 and one column-neighbor, key 5. This is confusing because a user cannot readily apply learned spatial relationships. In addition, any text associated with the keys will also have rotated and will be more difficult to read.
To deal with these difficulties WO 98/24103 and WO 99/48120 propose alternative keypad arrangements for mobile telephones, wherein numeral keys are disposed in a generally oval configuration.
However, such keypads are still difficult to use if the mobile telephone or device is used in an alternative orientation. Therefore, what is needed is a device with a keypad that can be rotated with respect to the device""s body without loss of spatial orientation.
Accordingly, a device is provided that includes a body, a display, and a keypad, wherein the keypad may be rotated with respect to the body.
In this way it is possible for the orientation of the display to be changed with respect to the body while the body is rotated about the keypad. This may be used to maintain a particular orientational relationship between the keypad and the display. This may be useful in allowing the mobile terminal to be used in alternative orientations.
The keypad may be rotated by a user to optimise the electrical device for both horizontal and vertical viewing modes. It is particularly convenient in providing ready right- and left-handed usability. In this way it is possible for a user to change use of such a display from a portrait mode to a landscape mode while maintaining the orientation of the keypad.
In an embodiment, the keys are circularly disposed in numerical order, and their positions and their sequence have a logical correspondence. This can provide a convenient keypad wherein location of the keys is straightforward.